Transmitter



Feb. 16, 1943. M. w. lwlJlsHTEl-` TRANSMITTER Filed June 15..'1940 ATTQRNEY' Patented Feb. 16, 1943 UNHTED STESQPATE .TRANSMITTER Manfred W. Muehter, Nutley, N. J., assigner to American District Telegraph Company, Jersey City, N. J., a corporation of New Jersey Application June 15, 1940;'Seria1 No. 340,696

This invention relates generally to signalling A 13 Claims.

systems and more particularly to those systems wherein itis desirable that code signals received at a central oce be retransmitted either to an audible signal receiver or to a recorder or indicator at a remote point such as for example a"' which is either the same as the received code or diierent in the number of digits and the number of rounds which are retransmitted. Therefore, it is'further desirable to provide a simple arrangement for transmitting a code cc-mprising any desired number of digits and any desired number'of signal rounds.

Accordingly, the principal object of this invention is to provide asimple and efficient signal transmitter.

A further object of this invention is to provide a code transmitter in which the number of rounds may be determined and transmitted at the will of the operator, andin which any code number may be transmitted from 1 to 9,999.

A-still further object of this invention is to provide a signal transmitter which .is simple in loperation and economical in maintenance.

Further objects and advantages of this invention will be apparent to those skilled in the art upon consideration of the following specication and the accompanying drawing, wherein:

The single figure Yof thedrawing is a circuit diagram which illustrates a preferred embodiment of "the invention.

This'invention is adapted for use in any signalling system such as that comprising atrans- `mission line including a number of transmitting stations for transmitting code signals and a central ofce where such code signals are received and recorded or otherwise indicated. In some installations it is not feasible to provide automatically operated apparatus for retransmitting such signals to local audible signal devices or remote audible signal devices and recording devices. Therefore, in accordance with this invention, a signal transmitter is provided which is Iio adapted totransmit any desired code signal and any desired numberoi rounds of such asignal.

The invention will be described generally inV order to convey a preliminary.understanding thereof. When a-code'signal is to betransmitted,

the operator sets up that sig-nalen the code keyboard I2, which comprises four rows of push buttons or other circuit closing or opening devices, the push buttons being arranged in a thousands row,a hundreds row, a tens row, and aunits row, whereby a four digit code-signal .may be set upl by selecting and operating a button from each of the rows. The transmission is actually initiated by momentary actua-tion of start button I, which in turn operates animpulse generating circuit comprising the relays 5 andi, Ythese relays'being arrangedto short-circuit one another-in succession. The relay is provided with a number of switching contacts Vto control abode selecting switch ST whichis made up of three separate banks of fifty contacts each and which is `stepped intermittently in accordance with the successive operations vof relay 5.

.Bank I of the selecting switch performs a switching function in conjunction with-the relay 5 and a switch relay 9, while bank 2 of the selecting switch actually selects the code which is set up on the keyboard I2.v Bank 3 of the selecting switch establishes a shunt circuit around the starting buttonk I, whereby the battery current is maintained across the starting button after its momentary actuation. The push buttons are Vcofnnected'to the second bank of the selector switch ST in such a manner that the zero button in the thousands row is connected to Contact 2 of the selector, and the other buttons are connected in sequence to the following contacts up to contact II, contact l2 being left blank to determine the end of the thousands digit.` Thehundreds row of buttons is connected in sequence to contacts I3 to 22 of the selector switch, contact 23 being left blank to determine the end of the hundreds digit, and the buttons in the tens row are connected in sequence to contacts 26 to 33, contact 34 being' left blank. The buttons in the units row are connected to ycontacts 35 to 44 of the switch, while contact 45 is directly connected for the purpose of carrying the operation of the circuit over into a subsequent round.

The l switching operations are controlled through a number of parallel circuits. When the code has .been set up and the transmitter started and selector ST `has reached position l2, it is stepped in self-energizing fashion through the lli "iO'rLST- I, Y Y, f n Theselector CSV isha round counting selector .which controls transmissionv o f'a. plurality of l A'to positive'battery. plies a shunt by its contact I across relay 5, which icauses this relay to become deenergized. Relay 5, acrcssthelrelay 1, which again releases. completes one cycle of operation of the pulse genstepping magnet STS to plus battery, thereby actuating the stepper armature. Upon the rst shunting and release of relay 5, STS becomes deenergized, advancing the selector ST to position I. Selector bank ST3 thereafter shunts pushbutton I and maintains the battery connection slowly in accordance with the operation of relay 5 to count the first digit of the code. A end of this digit switch ST reestablishes a shunt 'At the` u circuit around relay 9 so that the self-energizing circuit again causes switch ST to make afserie's of fast steps until the button in the second row is found by bank 2 of the switch.- kThe counting function is continued in this fashion, relay 9 being energized by the action of switch ST to cause transmission of each code digit. 4

' vActual transmissionofthe signals is controlled bylrelay 5 and relay 9, relay 9 closing the transmissioncircuit v:Vttits contact I and relay 5 causgx'ttransmission torreceive'r I5 of thecode 'digits n, determined vby tank. 2 @fselecrou'n'ds'under the control'of the buttons B2, B3, andiB 4. The ,relay S'through its Ycontact 2 establishes a `first circuit for energizing the Vswitch `CS'whereby,one round is always transmitted. If forinstance three rounds are `to betransrriitted,

thebuttonQB isoperatedto open the stepping .circuit wfor` switch CS, whereby at the end of the wd round the switch -returns to its normal positionand opens ,the fctrl-normalv contact which it controls through acam, tow thereby completely d energie@ the transmitter and,V stop its operation.

detailed description ofthe operation of the `iici1irwi11-new be given in connection with the drawing. L

Y Circuit operation fus' assume thata three roundv code loff4-''F-2--3"is to be retransmitted. The fourth button in thousands row shall be pressed, the fth Vv'inthe hundreds; row, the second in the `tens row "and the third in the units row. The round-selecting button (in this case B3) shall be-pressed.

1;::The'momentaryl closing -of the pushbutton switcht Izapplies minus battery `to the coil of relay 5',-f.through the circuit traced from minus battery,v `:through the'starting button I; through the coil of relay51and resstor to plus battery. The-op- 5,?frorn` minus batteryjthrough relay 1, resistor The operation of relay I ap 5` Vagain in turn applies the shunt, by its contact This erating relays 5 and 1 and this cycle of-pulsing is repeated as long as power is supplied from bat- 'f v'Upon-the first operation ofk relay 5, at .the start nf a transmission. a circuit is closed from minus .through-the starting button I. throughcode selector ST, bank- I, at contact 50, through contact I of relay 5 upon its first closing, through selector Nit'sQcontact 4.; the relay 9- prepares the "transmission circuit and relay 5 4controls code *transmission as l of relay 9, interrupter contact of stepping magnet STS, stepping magnet coil STS, to plus, selector ST advancing to position 2 on the break of theinter rupter contact of stepping magnet STS.

At position 2,1 the winding I of the relay 9 is connected to minus battery but does not operate due to the shunt across its winding by the Contact of bank 2 of selector ST at position 2, through the button 9 of the thousands row in switch I2, and back contact 5 of relay 9.

At position 2, the previous stepping circuit for ST is opened on bank 'I but a second circuit is closed from minus battery through bank 2 of ST, through the closed pushbutton 0 on the Vkey switch I2, through break contacts 5 and 'I of relay 9,'interrupter contact of magnet STS of the selector and the selector stepping magnet STS to plus battery. Whentheselector becomes energized, it breaksV its own stepping circuit at the contactvof stepping magnet STS,V thereby advancing the selector to position 3. This self-stepping circuit is completed by the various buttons 9, 8, 1, 6, etc. on the thousands row, the selector advancing to a point at which there is an open caused bythe operation of a button (for the code being discussed, this will be button 4 connected to position B of bank 2 of ST).

Whenthe selector ST reaches position 8, the shunt across the winding I of relay 9 is removed, due to the open at button 4relay 9 thereforeI operating through the circuit traced from minus through bank vI position 8, through `winding I of relay 9, through break Contact 2 of relay 5 and backv contact 'I Aof relay 7 9, through the interrupter contact and coil STS to plus. will not be advanced at this time due to the fact that the current through its winding is limited to a low value by the added resistance of winding I of relay 9. The operation of the make-beforebreak contacts 6 and 'I of relay 9 causes this re-v lay to lock in through its coil and the resistance winding 2 to plus battery.

The operation of relay 9 at this time closes a new stepping circuit for the selector ST from minus battery, through make Contact 3 of relay 9, through pulsing contact I of relay 5, through'the coil STS to plus battery. Contact 2 on relay 9 at this time closes a circuit from minus battery, through contact 2 of relay 9, through position II (normal home position) on bank I of counting selector CS through the interrupter contact of stepping magnet CSS, make contact 5'of relay Sand stepping coil CSS to plus. Selector CS becomes energized but immediately breaks into its own circuit and advances one step. At position I there is no power available for further self stepping due to the open in the circuit at round button 3. The cam operated off-normal contacts CSC of ,switch CS shunt the starting button I and bank ST3 establishing a second circuit for maintaining battery connection.

The operation of the break contact 5 of relay 9 opensthe shunt circuit of bank 2 caused by the remainder of the pushbutton keys in one row.

The stepper yof .the code.

relay and locks inrelay'I. The selector VST `will then bestepped by the operation of'the contact I of .relay 5, advancing the selector to Yposition I2, making in all four slow steps for the first digit At position I2, the circuit through the winding I of relay 9 will be interrupted at bank I, position I2, thereby releasingitbut a stepping circuit previously traced through bank I and contact 3 of relay`5 is completed, the only dierence being'at this time through position I2 instead .of position I. Upon reaching 'position l I3, a similar shunt circuit is completed across the 'winding I of relay 9 `and an interrupter circuit is again set up'for the stepping coil STS similar to that previously described at position 2. The se- 'lector' ST will become self-interrupting and ad- Y.Vance .to aposition as determined :bythe open in the pushbuttons connected to bank 2; in the case of the second digit for the code discussed this will be-button 5 connected to position I8 of ST2. `At this point relay 9 will energize againand the se- -lector STwill make five slow steps asdetermined by 4the operation of .the pulsing fcontact I of relay 5.

The remainder of the digits ofthe code .are

transmitted in a manner similar to that previously described.

Upon reaching position of the selector at the end of the last digit, the relay 9 releases, .as

previously described, and an additional step is made from 45 to 49, through a circuit -which may be traced through contact 45 .of bank ST2,

through back contact 5 of relay 9, break contact I of relay 9, interrupter contact and coil of STS;

to plus battery. At positions '46 to '50 iivesteps are `made through theoriginal stepping circuit -described through bank -I, through-positions V46 to 5D and contact I of relay 5, and coil STS to plus battery. This permits an interval between rounds` Atiposition-49, countingselectorCS is energized through the circuit traced fromminus battery, through the ST selector bank 2 to-position 49, through make contact 6 of frelay'5 and coil.

through button B4,.position 3 of bank I of CS,

the interrupter contact of coil CSS, make contact 6 of relay 5 and coil CSS to plus-causing the selector to advance to position 4. A similar self-stepping circuit through points 4 to 9 of bank I advances the selector CS to position1I-0.60

Following this, thethird round is transmitted. When selector ST reaches position '49, selector CS is energized through a circuit previously traced, Amoves to position I I on'the release of relay `5, and opens its cam operated contacts CSC. At the same time selector ST advances `from 49 to 59 and .removes the connection to battery through bank 3. Therefore the transmission stops and restoration of the code keyboard push buttons and theround selecting buttons to their normal closed positions leaves the transmitter in its normal condition and in condition for subsequent selection of a new code.

Retransmission of either 1, 2.0124 rounds is .accomplished in asimilar manner, the .control vby buttons B2, B3 or B4 determining the V stepping :circuit 'for selector CS.

VVCoding operation From the previous descriptiomit will be recalled that CS moves from its normal homeposition-II on the rst operation of relay 9. Also, that this relay operates at the start of codje transmissionand remains energized'during each `digit during which time the equipment is con- .trolled by the operation of relay 5. Therefore the coding circuit will be closed each time contact 4 of relay 5 closes, for a number of operations depending on the code set up.l The. transmitting system as described abov `may be adapted for transmission of signalsto any form of signal receiving device. -For pur- .poses of illustration a conventional signal recorder I5 is shown connected ina series-with a source ofY current, Contact 4 of relay 5, contact I of relay 9, `contact :II of switch CS, `and `tapper button Iii, Thus a code of four digits or lessmay-be transmitted to the signal receiver I5wunder-the con-trol ofv either contact 4 of relay 5 or themanually-operated tapper button I5. l f

-Frorn the above description it is evident that this invention provides a transmitting device whichis adapted totransmit code signals com- .prising one or more digits and also comprising Aone or more successive rounds. .It is -obviousthat `the push-buttons on the keyboard may be replaced by any form of manual -or automatic circuit opening device whereby the transmitter may be either manually lor automatically operated from a "remotepoint in response to signals re- -ceived -from signalingsystems such as those in .everyday use for supervision of fires, burglary, vor watchmans supervisor signal systems.

Further modifications of this invention -will be evident'tothose skilled in the art, and `therefore .it is desired that this invention-shall be limited y.onlyby the prior art andthe scope of the appended claims. v

`I claim:

1. In' an impulse code transmitter for transmitting impulses over an electric circuit, selector Ymeans includingastepping switch having a series -of4 contacts Vand a switch wiper engaging said `contacts, digitkeys connected to the respective contacts for setting up the code to be transmitted, pulsing means for operating said -swltch wiper vto close control circuits successively through said digit keys and means controlled by said .control circuit and 'the particular key that .is operated for transmitting impulses over said -first-mentioned circuit-during subsequent steps vof theswitch, said last-mentioned means includ- .ing said pulsing means. f

2..In an impulse code transmittervfor transmitting yimpulses over fan electric circuit, a stepby-step switch having a series of bank contacts, digit keys kconnected to the respective contacts .for setting up the code to be transmitted, pulsing means for operating said switch to-close circuits successivelythrough.said digit keys and means controlled by the particular-keythat is. operated for transmitting impulses over lsaid circuit duringsubsequent steps of the switch, said lastmenti-oned means including said pulsing means, .said step-by-step switch and a relay having a `winding connected` to contacts of the respective digit keys, contacts of said relay being' interposed in the transmitting circuit.

3. In an impulse code transmitter for transmitting impulses over an electric circuit,a .counting "ste'p-by-step switch having`a series of bank contacts, digit keys connected to the respective contacts for setting up the code to be transmitted, an impulse generator for operating said switch to' close stepping circuits successively through said digit keys for stepping said switch and means controlled by the particular key that is operated for transmitting impulses over said 'circuit duringsubsequent steps of the switch,

said last-mentioned means including said pulsing means and-contacts operated thereby, said stepby-step switch and a relay having a winding shunted by contacts'of the respective digit keys,

certain contacts of said relay being interposed in the transmitting circuit whereby an open digit key removes the shunt from said winding and the relay operates.

4. In a transmitting circuit, a source of impulses, a transmitting circuit operated by the source of` impulses, a receiver connected thereto, circuit controlling Ameans between the receiver andthe transmitting circuit, a relay for actuat- :ing'the circuit controlling means, a plurality of groups of code keyseach keyl being adapted to control the relay and transmission of a digit,

aselectr means connected inseries with the keyswhereby code transmission starts when the selector establishes a connection to an Voperated key and a second selector for controlling actuation of the relay at the end of a digit, whereby code digit transmission is started by the rst selector and terminated by the second selector.

5. In a transmitting circuit, a source of impulses, a' transmitting circuit operated'by the source of impulses, a receiver connected thereto,

circuit controlling means between the receiver and the transmitting circuit, a relay for actuating the'circuit controlling means, a plurality of groups of code keys each key being adapted to `control the relay and transmission of a digit,

'a selector bank the contacts of which are connected to the code keys for switching successively from key to key within each group of keys for starting operation of said relay when the selector establishes a connection to an operated key and v -a vsecond selector in circuit with the first selector for controlling actuation of the relay at the end vof -a digit whereby code digi-t transmission is 'started by the rst selector and terminated by the second selector.

6L In -animpulse code transmitter for transmitting signals,. a key controllable code selector including movable switch wipers and cooperating banks of contacts for setting up a code and controlling its transmission, a key controllable count- 'mitting impulses over an electric circuit, a stepping switch having a series of bank contacts, a stepping magnet, an interrupter contact controlled by said magnet, digit keys connected to Athe` respective contacts of the stepping switch and to each other which when operated set up a code to be transmitted, switching contacts for establishing a circuit through the stepping switch,

the keys, the stepping magnet and its interrupter contact. whereby the stepping switch is initially self-steppingthrough each closed digit key, a switching relay connected in shunt to the stepping switch and the digit keys which becomes actuatedy and locked when the stepping switch establishes a connection to an open digit key, and which'a'ctuates the said. switching contacts to break the self-stepping circuit, an impulse generator, a second stepping circuit including switching contacts in series with the stepping magnet of the stepping switch and controlled by the impulse generator and the switching relay whereby the stepping switch steps and counts successive impulses from the generator, a transmitting circuit including contacts controlled by the impulse generator and the switching relay whereby counted impulses are transmitted as a code digit and a second stepping switch controlled by the same stepping magnet for actuating the switching relay at the end of the digit which in turn actuates its contact in the second stepping circuit and its contact in the transmission circuit to terminate transmission of the digit.

8. In an impulse code transmitter for transmitting implses over an electric circuit, a stepping switch having a series of bank contacts, a stepping magnet, digit keys connected to the respective contacts of the stepping switch and to each other which when operated set up a code to be transmitted, switching contacts for establishing a circuit through the stepping switch, the

keys, the stepping magnet and its interrupterr contact whereby the stepping switch is initially "self-stepping through each closed digit key, a

switching relay connected to the stepping switch and the digit keys which operates when the stepping switch establishes a connection to an open digit key, and which actuates the said switching contacts' to break the self-stepping circuit, an impulse generator, a switch controlled by the switching relay for energizing the stepping switch whereby it counts successive impulses from the generator, a transmitting circuit includingcontacts controlled by the impulse generator and the switching relay whereby counted impulses are transmitted as a code digit and a second switch for actuating the switching relay at the end of `the digit to terminate transmission of the digit.

9. In an impulse code transmitter for transmitting impulses over an electric circuit, a stepping switch having a series of' bank contacts, digit keys connected to the respective contacts of the stepping switch which when operated set up a code to be transmitted, a'switching-relay connected to the stepping switch and the digit keys which becomes actuated when the stepping switch establishes a connection to an operated digit key, an impulse generator, a second circuit including switching contacts in series with the stepping switch and controlled by the impulse generator and the switching relay whereby the stepping switch steps and counts successive impulses from the generator, a transmitting circuit including contacts controlled by the impulse generator whereby counted impulses are ltransmitted as a code digit and a second switch for actuating the switching relay at the end of the digit to terminate transmission of the digit.

10. In an impulse code transmitter for transmitting impulses over an electric circuit, a selecting means having a series of contacts, digit keys connected to the respective contacts of the selecting means which when operated set up a code to be transmitted, .a switching means connected to the selecting means and the digit keys which becomes actuated when the selecting means establishes a connection to an operated digit key, an impulse generator, a second circuit including switches connected with the selecting means and controlled by the impulse generator and the switching means whereby the selecting means counts successive impulses from the generator, a transmitting circuit including transmitting means controlled by the impulse generator whereby counted impulses are transmitted as a code digit and a second switch for actuating the switching means at the end of the digit to terminate transmission of the digit.

l1. In a transmitting circuit, an impulse generator, a source of current, means for connecting the source to start the generator, a pair of transmitting contacts operated by the impulse generator, a receiver connected thereto, switching contacts connected between the receiver and the transmitting contacts, a switching relay for controlling the switching contacts, a shunt around the switching relay comprising a plurality of groups of normally closed push-button switches each switch being adapted to be opened to con- -trol transmission of a digit, each group being assigned to control the transmission of a given digit of a code signal, a selector switch comprising groups of contacts connected in series with the groups of push-button switches whereby code transmission starts when the shunt is broken and the switching relay operates to cl-ose the switching contacts, a second selector controlled by the first selector for preparing a circuit through the switching relay and breaking such thereto, switching contacts connected between the receiver and the transmitting contacts, a switching relay for controlling the switching contacts, a shunt around the switching relay comprising a plurality of groups of normally closed push-button switches each switch being adapted to be operated to control transmission of a digit, each group being assigned to control the transmission oi a given digit of a code signal, a selector switch comprising groups of contacts connected in series with the groups of push-button switches whereby code transmission starts when the shunt is broken and the switching relay operates to close the switching contacts, a second selector for preparing a circuit through the switching relay and breaking such circuit at the end of a digit, whereby code transmission starts when the shunt circuit is removed by the first selector and the second selector operates the switching relay which in turn completes the transmission circuit until a digit is transmitted. y i

13. In a transmitting circuit, an impulse generator, a pair of transmitting contacts operated by the impulse generator, a receiver connected thereto, switching contacts connected between the receiver and the transmitting contacts, a switching relay for controlling the switching contacts, a circuit for normally disabling the switching relay comprising a plurality of groups of normally closed push-button switches each switch being adapted to control transmission of a digit, a selector means comprising contacts connected in series with the push-button switches whereby code transmission starts when the disabling' circuit is operated by the selector means and the switching relay operates to control the switching contacts, a second selector means for controlling the switching relay and operating it at the end of a digit, whereby code transmission starts under control of the first selector and the second selector operates to in turn terminate the transmission of a digit.

MANFRED W. MUEHTER. 

